Background: The series will be decided over the course of a week, but in many ways this matchup is about the past three years. The season is on the line for two of the league's model organizations. Legacies are on the line as well.

Since the 2012 season began eight months ago, the Sounders' mission has been crystal clear: Win when it matters most. The three U.S. Open Cup titles, massive crowds and modest CONCACAF Champions League success certainly have been nice, but the club's 0-for-3 record in MLS Cup playoff series remains a shadow from which coach Sigi Schmid and his players must escape.

"As great as the Open Cups and that stuff as been, the only thing people seem to remember is not advancing in the MLS playoffs," Seattle veteran Brad Evans told Sporting News.

"There is no magic formula," Schmid told The Seattle Times. "It's a matter of us going out there, and we know what it takes. We've been through the experience. We've been through the disappointment. And the desire not to have that disappoint again has to be very strong."

Real Salt Lake enjoyed early playoff success, advancing to the semis during its first postseason foray in 2008 and then winning it all the following year. Oddly, that championship was the start of big things for the small-market club, not the conclusion.

RSL came within a goal of winning the CONCACAF Champions League, advanced to the MLS playoffs five consecutive times (the longest streak in the league) and became only the second club to earn at least 50 standings points three consecutive years.

At the heart of RSL's success has been a core of 10 players who've been together for five seasons — no MLS team ever has enjoyed such continuity.

Now, with hints of offseason roster turnover in the air and several younger players on the verge of cracking that core, there’s a sense this RSL team needs one more trophy to be considered among the best in league annals.

"It's been a while since we've won something," Kreis told reporters Thursday. "We've certainly been close a whole lot of times. And you don't get close by being lucky. You get close, you get an opportunity to win things, by being good. And so we've done a lot of very, very good things to get close a number of times. ... It would certainly be nice to win something again."

One of those dreams will be extinguished next week.

Outlook: Three games between Seattle and RSL produced one goal. These squads are evenly matched, experienced and tactically astute. For soccer purists, this is the best matchup of the quarterfinal round.

"All the games we've played have been pretty attack-oriented, exciting games with lots of chances," Kreis told KTVX-TV. "For whatever reason, the ball hasn't ended up in the back of the net very much. I wouldn't expect things to be too different."

Seattle will enjoy home-field advantage in the first leg but likely will play Friday without striker Eddie Johnson (14 regular-season goals), who is recovering from an injured hamstring. In his absence, RSL can watch Seattle's Fredy Montero (13 goals) more closely.

"If they are missing (Johnson), they are missing a key component. Hopefully, we could take advantage of it,” Kreis told The Salt Lake Tribune.

But RSL's attack hasn't exactly been humming lately, either. Shut out in the final two regular-season games (including a 0-0 draw in Seattle), Kreis' side must get a command performance from Álvaro Saborío, who quietly finished third in the golden boot race with 17 goals. But it won't be easy — first-year goalkeeper Michael Gspurning has been outstanding and the Sounders quality team defending resulted in the league's second-lowest number of goals against.

Assuming RSL central defenders Nat Borchers (quadriceps) and Jámison Olave (hamstring) are 100 percent, the visitors will look to lock down Montero, establish some possession through Javier Morales and head back to Rio Tinto Stadium with at least a draw.

For the hosts, Montero and midfielder Mauro Rosales (who missed last year’s series between the clubs) must be at their creative best to give Seattle the chance to end their playoff hex.

“This one, we know what its’ all about,” Montero said via the league's website. “If you can use the good pressure to motivate and jump onto the field and try to do everything you need, it’s going to be good for the team.”